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One expert largely credits a Chinese drug ban that went into effect in October

(CNN)In late 2014, the synthetic drug known as flakka exploded on the scene and prompted such bizarre, violent behavior that it quickly became shorthand for lunacy. The street drug, which is similar to cocaine but much cheaper and more potent, has been called "$5 insanity."

State authorities warned about the health dangers of using flakka, which comes in white crystals that can be snorted, ingested or injected. Being around users could also be dangerous: Reports circulated of a man breaking down hurricane-proof doors and a woman running naked through the streets, both allegedly while high on the drug.

But then, just as quickly as it came on the scene, flakka seems to have nearly vanished. Sixty-three users died in South Florida between September 2014 and December 2015, but there have been no flakka-related deaths in 2016. Treatment centers in Broward County, Florida, admitted only six flakka users in January, compared with about 50 a month in the fall.

Flakka crystals can be snorted, ingested or injected.

"Anecdotal reports from both street users and law enforcement officers say that flakka is not even available in the street drug market," said Jim Hall, a drug abuse epidemiologist at Nova Southeastern University in Fort Lauderdale, Florida.

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"I have never seen an epidemic emerge so rapidly but literally disappear so quickly," he said.

The popularity of flakka has also plummeted in areas such as Chicago, Houston and rural parts of Kentucky and Illinois, he added.

The main force that stemmed the flakka surge, Hall said, was a Chinese ban on the production and exportation of alpha-PVP, the chemical name for flakka, along with 115 other street drugs.

The United States and Europe put pressure on China to ban these substances, and the Chinese government acted swiftly. The ban went into effect October 1.

"They did not want to become known as a narco (or narcotic) nation," said Hall, who met with government officials about the problem.

It probably helped that nearly all of the labs that made flakka were in one Chinese province, just north of Hong Kong, Hall said. "It was primarily a single supply source. This was not an international drug cartel with major operations and different systems. We could shut it off right at the source."

But don't celebrate the end of flakka just yet. In 2014, China banned methylone, a synthetic stimulant in the same family as flakka that was added to ecstasy or "Molly." Methylone disappeared, only to be replaced by an analog substance called ethylone. And after ethylone was included in the 2015 ban, it has been replaced by dibutylone, Hall said.

Flakka itself is related to a group of drugs known as "bath salts," which were banned in 2012.

"History has shown that one of the unintended consequences to banning certain drugs is that it typically leads to an explosion of new replacement drugs. Whether that will happen (with flakka) in response to the 116-drug ban is impossible to tell at this point," said Michael H. Baumann, director of the Designer Drug Research Unit at the National Institute on Drug Abuse's Intramural Research Program.

Another question, Baumann said: "Will some other country pick up the slack if China is not making it?"

Hall suspects that there has been no sign of a flakka replacement because it had a bad reputation, even among those who used it. "Active users despised the drug but were addicted to it and compelled to use it," he said.

Maybe as a result there is not really demand for a stand-in for flakka, which gets its name from the Spanish word "flaca," for a thin, attractive woman.

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Public awareness around flakka also played a key role in the slowdown. "I've never seen a community come together so unified and focused on a specific drug problem as Broward County did with flakka," Hall said.

The local United Way created a team of community leaders, including paramedics and mental health counselors, that held almost nightly town hall meetings to educate the public about the dangers of flakka and places users could go for help, Hall said.

Baumann agrees that such public health campaigns can be very effective. "I think this might have even played just as big a part as having the drugs banned," he said.